Cause of fatal vintage plane crash in Switzerland remains a mystery

On Saturday, a plane constructed in 1939 crashed in the Alps while flying from Locarno to Dübendorf, just outside Zurich, leaving all 17 passengers and 3 crew dead.

Source: Graubunden Police

The Junkers JU-52 aircraft, flown by the company Ju-Air, crashed at 2,540 metres on the side of Piz Segnas in the Swiss canton of Graubunden.

The aircraft, one of four flown by Ju-Air, left Locarno on Saturday at 4.10 pm bound for Dübendorf. It was returning from a two-day sight-seeing flight.

Less than an hour into the flight, at around 5:00 pm, the plane crashed on the western flank of Piz Segnas. All occupants died, including seven couples from the cantons of Zurich, Thurgau, Luzern, Schwyz, Zug and Vaud, and a couple and their son from Austria along with three crew members from the cantons of Thurgau and Zurich, said police from the canton of Graubunden.

On its website, the company said the Ju-Air team is deeply saddened and offers its thoughts to the passengers, the crew and the families and friends of the victims. In addition, it has voluntarily suspended all flight operations to show respect to the victims, their relatives and friends, and to give the team time to reflect on the disaster.

A witness says the plane plunged rapidly from the sky.

So far experts interviewed by RTS have ruled out a collision or an inflight explosion. The pilots were described as highly experienced, and the aircraft was serviced as recently as July. One possibility is the aircraft stalled. This happens when insufficient air flows over the wing to create lift. This was the cause of the crash of Air France Flight 447 between Rio and Paris in 2009.

The 79 year-old aircraft, had no black box, something which adds to the challenge of establishing the cause of the accident.

Source: Wikipedia

The JU-52 was the main transport aircraft of the German Luftwaffe in World War II and has been flown by air forces and civil operators around the world.